How do fish survive in freezing water?

Fish in freezing waters survive due to specialised adaptations like antifreeze proteins in their blood, which prevent ice crystals from forming. Some species, like Arctic cod, have lipids that insulate their bodies. Additionally, many fish can reduce their metabolic rate, conserving energy in cold conditions. Their gills and circulatory systems are also adapted to extract oxygen efficiently from cold, oxygen-rich water, ensuring survival in extreme environments.